A number of our people have narrated from Sahl ibn Ziyad from Uthman ibn Isa from a number of our people has narrated thefollowing:

"When Abu Jafar Imam Baqir (as) passed away Abu Abdillah Imam Sadiq (as), commanded to light a lamp in the house where he lived until Abu Abdillah Imam Sadiq (as) passed away. Thereafter Abu al-Hassan Imam Kazim (as) did a similar thing in the house where Abu Abdillah Imam Sadiq (as) lived until he was taken to Iraq and thereafter I do not know what happened."

[Source: al-Kafi, Vol. 3, Pg. 251, Hadith. 5]

* You will see in Karbala many people lighting candles on the night of 11st of Moharram. And this act would be considered Mustahab based on the above narration.